Differential Photonic Emission Analysis

This work presents the first differential side channel analysis to exploit photonic emissions. We call this form of analysis Differential Photonic Emission Analysis (DPEA). After identifying a suitable area for the analysis, our system captures photonic emissions from switching transistors and relates them to the program running in the chip. The subsequent differential analysis reveals the secret key. We recovered leakage from the datapath’s driving inverters of a proof of concept AES-128 implementation. We successfully performed DPEA and were able to recover the full AES secret key from the photonic emissions. The system costs for an attack are comparable to power analysis techniques and the presented approach allows for AES key recovery in a relevant amount of time. Thus, this work extends the research on the photonic side channel and emphasizes that the photonic side channel poses a serious threat to modern secure ICs.